Pakistan’s government has been accused of signing the “death warrant” of Asia Bibi after it said it would begin the process of preventing her leaving the country.

Bibi, a Christian farm labourer, was acquitted of blasphemy on Wednesday. She had spent eight years on death row after she drank from the same cup as a Muslim, prompting false allegations that she insulted the prophet Muhammad.

Bibi’s lawyer, Saif-ul-Mulook, has reportedly since fled the country amid fears for his life, telling AFP: “I need to stay alive as I still have to fight the legal battle for Asia Bibi.”

The ruling Pakistan Tehreek-e-Insaf (PTI) administration signed an agreement with the anti-blasphemy group Tehreek-e-Labbaik Pakistan (TLP) on Friday night, giving in to many of its demands in the face of massive, countrywide protests calling for Bibi to be put to death.

In a document signed by the PTI’s religious affairs minister and the TLP’s second-in-command, Pir Afzal Qadri, the government promised not to oppose a court petition to reverse Bibi’s release. It also pledged to work in the meantime to put her name on the exit control list (ECL) which would prevent her leaving the country.

“Placing Asia Bibi on the ECL is like signing her death warrant,” said Wilson Chowdhry of the British Pakistani Christian Association. Bibi, a mother of five, remains in the same prison where last month two men tried to kill her, although she has been shifted out of her windowless cell.

The agreement was a “historic capitulation”, tweeted analyst Mosharraf Zaidi. On Wednesday night, the prime minister and leader of the PTI, Imran Khan, defended the verdict acquitting Bibi and suggested the government would clamp down on protesters it termed “enemies of the state”.

The TLP has agreed to call off its protests, which saw thousands of Islamists blockade the country’s major motorways, burning cars and lorries and chanting that they were ready to die to protect the honour of the prophet.

Meanwhile, the government has promised to free any TLP workers arrested during the three-day protest. The group has only apologised for the damage it caused, the cost of which one government official estimated at $1.2bn (£900m).

Afzal Qadri told the Guardian “the government has almost accepted our maximum demands” and that if it backtracked “we can come [out on the streets] again”.

Islamists poured on to the streets after Friday prayers in a show of force that briefly unified extremist groups from the majority Barelvi sect, which the TLP springs from, and the more traditionally hardline Deobandis. Terrorist-linked outfits including Ahle Sunnat Wal Jamaat held rallies in Islamabad, alleging that the EU had pressurised the government into releasing Bibi.

While the protests were ongoing, unknown assailants stabbed Sami ul Haq – the leader of the Haqqania madrasa known as the “father of the Taliban” – to death in his own home.

The spokesperson for Pakistan’s army, Maj Gen Asif Ghafoor, said that the military’s chief condemned the assassination and expressed “grief and condolences” for the ul Haq family. Earlier in the day, Ghafoor released a statement about the protests which avoided criticising the TLP, despite its leaders calling for soldiers to mutiny.